pH-Responsive Smart Non-Woven Fabrics (NWFs) with Double Switchable Wettability between Superhydrophilicity −Superhydrophobicity−Superhydrophilicity to Oil/Water Separation

pH-responsive smart Non-woven fabrics (NWFs) with double transformations are prepared via in-situ grafting Ag nanoparticles through an oxidation-reduction reaction and modified with a mixed thiol-molecule solution, including HS(CH2)10CH3, HS(CH2)10COOH and HS(CH2)11OH. NWF continuously separates immiscible oil−water mixtures with high selectivity and considerable flux Under gravity. The wettability of NWFs with optimal thiol concentration shows reversible switches between superhydrophilicity-super hydrophobicity-superhydrophilicity which corresponds to different conditions such as acidic, neutral and basic. The as-prepared NWFs have great oil-absorption capacities and possess high oil-water separation efficiency. This simple approach to fabricate pH-responsive NWF has provided a facile and versatile strategy for effectively separating oil-water mixtures which can be further applied to water treatment, purification of solvent or fuel and so on.